This invention relates to a rail vehicle for transporting road semi-trailers.
Rail vehicles for transporting road semi-trailers are well known and comprise a flat rail vehicle with provision for retaining the road vehicle by means of a dummy fifth wheel plate and wheel troughs. The road vehicle is loaded onto the rail vehicle by means of lifting with a crane, or it is driven onto the rail vehicle by means of ramps and a special road tractor unit. In some countries with a small loading gauge the road vehicle wheels are also retracted into a pocket in the frame of the rail vehicle.
Some countries, particularly Great Britain, have a very restrictive loading gauge which makes existing vehicles unusable. Also the terminal costs for the existing systems are very expensive.
In an attempt to overcome these problems of terminal costs, rail wagons have been designed which enable a trailer to be loaded using the conventional tractor unit to drive the trailer on the and off of the wagon. The first proposals simply involved driving tractor trailer combinations along the length of a train and sequentially stopping the combinations at the last available space. This arrangement is disclosed in GB No. 1,190,963 and EPO 019,098 and has the disadvantage that loading and unloading times are long and the rail wagons have to be provided with removable buffing arrangements.
As improved arrangement involving the use of pivotably load bearing structures has also been proposed eg. in EP 023,372 and WO81/02142 but in these cases, the pivotable structure is centre pivoted and relatively high. An end pivoted arrangement has been disclosed in EP 181676 but again the combination of rail wagon and trailer is relatively high, which means that it is difficult if not impossible to comply with the loading gangs of many countries when using large trailers. Yet centre variation is disclosed in GB No. 901,275.
In our earlier patent application GB No. 2,179,311 a rail wagon is disclosed using swing-out section located intermediate end frames each of which carries conventional rail suspension and buffing. The swing-out section is connected to the end frames so as to maintain the structural integrity of the wagon in all locations of opening and closing of the swing-out section. However, experience with this construction has shown that over time it can become difficult to ensure smooth functioning of the swing-out section and locking of the swing-out section in the closed position.